Chop rather fine one good-sized, very sound, peeled onion. Melt two ounces of very good butter in a saucepan on a very brisk fire ; add the onions, brown them for six or seven minutes, or until they have obtained a good golden color ; then add ten ounces of well-picked Italian rice (a heaped cupful), with two good-sized chopped truffles ; stir well with the spatula without ceasing for one and a half minutes, then add one quart of boiling and strained white broth (No. 99), lightly stir once only, and cook for fourteen minutes. Add six fine chopped mushrooms, and little by little, at intervals, another quart of boiling white brothstirring almost constantly with the wooden spatula while cooking, very rapidly, for ten minutes more. Season with a heavy half-teaspoonful of salt, a light saltspoonful of white pepper, adding one and a half ounces of grated Swiss cheese, and a heaped teaspoonful of Spanish branch saffron, diluted in two tablespoonfuls of hot white broth, and strained. Cook for three or four minutes longer, stirring continually meanwhile ; then pour it into a hot soup-tureen, and send to the table with a little grated Swiss cheese, separate. A little beef-marrow can be added to advantage, by making a small cavity in the centre, while yet in the pan, one minute before the time to serve, and plunging into it one tablespoonful of marrow.